Power and ground from amp, so I only need switched power to head?

[Snail 10+ year member]

My head unit is an Alpine CDM 7874 and my amp is an Alpine MRP F200.

I just got back from an audio shop where the guy told me that because my amp is running all four of my speakers (six including the spliced in tweets), the only thing coming off the head is the blue remote turn on wire and the four RCAs. I thought I would have to run a power and ground wire from the head AND the amp. And what about the switched power (ignition) lead? He didn't say anything about that. Does that go from the head to a wire that gets power when the key is in the ACC position like before?

Would that mean that since the switched power lead is upstream of the source of power (the amp), this setup would always have my amp on, even when I'm walking away from my locked car? Or is that wrong, and all this guy forgot to mention was that the switched power wire needs to be hooked up too?

And assuming this guy is right (plus the ignition wire bit), where do I put the 15 amp fuse that's attached to the yellow power wire coming out from the head unit harness? The amp will have a 25 amp fuse so I'm thinking the 15 amp one needs to be in there somewhere. Does it go on the remote turn on wire?

So is this guy nuts or am I ignorant?

Thanx peeps.

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[Spddracer 10+ year member]

Are you using the factory harness with the adator that plubs into your car ? You will need power and acc power to the HU

 

[Snail 10+ year member]

Negative on the factory harness. I pulled ALL the stock wiring since it was a premium system with eight speakers and three amps.

So, no matter what is going on, the head will need it's yellow (power) wire hooked up to the positive side of the battery or something equivalent?

Thanx guys.

 

[Spddracer 10+ year member]

You are correct , It hooks up just like any other Stereo

 

[maylar 10+ year member]

The only difference between this install and any other is that the HU speaker wires won't go anywhere. All power, ground, remote, antenna, etc wires still have to be hooked up. That's basically what the guy was saying - you're only using the HU for it's preouts and remote functions. But it still needs power...

 

[Snail 10+ year member]

Totally answered my question(s). I appreciate the help.

Thankyou!

 

[Dreamworkz 10+ year member]

All u do is get a dash kit and wire harness and match up everyhting the same and hook it all up identical.